The increasing Internet traffic and the increased complexity and use of web applications has forced network providers and network infrastructure managers to seek enhanced transmission speeds for network equipment. The TIA/EIA set up a high-performance cabling category to fulfill this requirement often referred to as CAT 6.
Such high-performance cabling uses a format with RJ 45 jacks and plugs. The agreed to format for the lines at such a connector involves a line with a center pair of conductors at the connector and a split pair of conductors at the connector. One conductor contact of the split pair is on each side of the center pair conductor contacts. When such an RJ 45 plug mates with an RJ 45 jack with signals at such high frequencies (as per the standard), the split pair will suffer a significant Near End Cross Talk (NEXT) problem from the other pairs.
It is known that electrical signals of one pair of conductors may be coupled onto the other pair of conductors for compensating or canceling crosstalk. JP 64[1989] 20690 (JP '690) discloses a modular telephone jack with a crosstalk prevention function where a capacitor is installed within a housing. A printed circuit board has traces connected to the capacitors and also connected between insulation displacement contacts (IDCs) and contact springs of the jack. In FIG. 4 an arrangement is shown wherein the traces are used to form a capacitor, to counteract the crosstalk. These traces cross each other with left to right crossing. Discrete capacitors may also be connected between transmission paths to compensate crosstalk (FIG. 3). JP '690 shows the use of both discrete capacitors connected to interconnecting traces of a circuit board to reduce crosstalk in jacks as well as the positioning of the interconnecting traces of the circuit boards providing capacitive interaction to reduce crosstalk.
U.S. Pat. No. 5,997,358 (US '358) discloses an electrical connector that achieves high transmission performance (CAT 6) by providing compensation stages for introducing predetermined amounts of compensation between pairs of conductors. Two or more of such compensation stages are provided. A first compensation stage adds a compensation signal that is time delayed with respect to the other compensation stages. In the first stage compensating crosstalk is introduced between the pairs of a first predetermined magnitude and phase in a given frequency. In a second stage, compensating crosstalk is introduced between pairs that has a second magnitude and phase in a given frequency. The first stage magnitude is larger than the offending crosstalk and the second stage reintroduces the offending crosstalk. US '358 uses multiple compensation stages to compensate for phase issues because, at high frequencies, compensating crosstalk cannot be introduced that is exactly 180° out of phase with the offending crosstalk.